Hydrophobic CDR3 residues promote the development of self-reactive T cells

Studies of individual T cell antigen receptors (TCRs) have shed some light on structural features that underlie self-reactivity. However, the general rules that can be used to predict whether TCRs are self-reactive have not been fully elucidated. Here we found that the interfacial hydrophobicity of amino acids at positions 6 and 7 of the complementarity-determining region CDR3β robustly promoted the development of self-reactive TCRs. This property was found irrespective of the member of the β-chain variable region (V[subscript β]) family present in the TCR or the length of the CDR3β. An index based on these findings distinguished V[subscript β]2[superscript +], V[subscript β]6[superscript +] and V[subscript β]8.2[superscript +] regulatory T cells from conventional T cells and also distinguished CD4[superscript +] T cells selected by the major histocompatibility complex (MHC) class II molecule I-A[superscript g7] (associated with the development of type 1 diabetes in NOD mice) from those selected by a non–autoimmunity-promoting MHC class II molecule I-Ab. Our results provide a means for distinguishing normal T cell repertoires versus autoimmunity-prone T cell repertoires

The epidemiological and economic effects from systematic depopulation of Norwegian marine salmon farms infected with pancreas disease virus

Pancreas disease (PD) is a viral disease associated with significant economic losses in Scottish, Irish, and Norwegian marine salmon aquaculture. In this paper, we investigate how disease-triggered harvest strategies (systematic depopulation of infected marine salmon farms) towards PD can affect disease dynamics and salmon producer profits in an endemic area in the southwestern part of Norway. Four different types of disease-triggered harvest strategies were evaluated over a four-year period (2011–2014), each scenario with different disease-screening procedures, timing for initiating the harvest interventions on infected cohorts, and levels of farmer compliance to the strategy. Our approach applies a spatio-temporal stochastic model for simulating the spread of PD in the separate scenarios. Results from these simulations were then used in cost-benefit analyses to estimate the net benefits of different harvest strategies over time. We find that the most aggressive strategy, in which infected farms are harvested without delay, was most efficient in terms of reducing infection pressure in the area and providing economic benefits for the studied group of salmon producers. On the other hand, lower farm compliance leads to higher infection pressure and less economic benefits. Model results further highlight trade-offs in strategies between those that primarily benefit individual producers and those that have collective benefits, suggesting a need for institutional mechanisms that address these potential tensions